Plug.



0.11. GORDON.

PLUG.

APPLICATION FILED MAR.6}1916.

' 2 SHEETS-SHEET I- P-atehted (m; 28, .1919.

-"D; GORDDN.

PLUG.

APPLICATION FILED MAR. 6. I916. I Patented Oct. 28,1919.

lfisggfilgs' 2 SHEETS-SHEET 2 jay/ad flijdan UNITED STATES r DAVID D. GORDON, OF CHICAGO, ILLINOIS, ASSIGNOR TO BENJAMIN ELECTRIC MANU- FACTURING COMPANY, OF CHICAGO, ILLINOIS,

A CORPORATION OF ILLINOIS.

PLUG,

Application filed March 6.

' description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to plugs for making electrical connections, and'more particularly to that style of plugs called separable attachment plugs. My invention, has for its object the provision of a new and improved style of separable attachment plug, in the preferred form of which the separable member 'to which the cord is connected carries one of the contact elements which is adapted directly to establish electrical connection with one of the socket contact elements with out the interposition of an intermediate conducting portion onthe cooperating portion of the plug.

I will explain my invention more in de:

tail by referring tothe accompanying drawin'gs illustrating one embodiment thereof, in which Figure 1 is a longitudinal sectional view of a plug constructed in accordance with my invention as mounted in a socket;

Fig. 2 is a side View of the two plug members in their separated condition;

- Fig. 3 is a sectional view of the plug and the contact portion of thesocket on line a of Fig. 1;

looking at the separable part of the attachment plug in the direction of the arrow 71in Fig. 2;

Fig. 5 is a sectional view of a modified form of socket;

Fig. 6 is a top View thereof;

7 is a longitudinal view of a plug adapted to coeperate with the socket of Fig. 5;

Fig. 8 is a view looking toward the contact making portions of the separable part of the plug shown in Fig. 7, and

Fig. 9 is a side view of the plug shown in Fig. 7

Referring more particularly to Fig. 1, I show a socket 1 having the central contact element 2 and the outer screw threaded contact element 3. My improved plug 4 is adapted to cooperate withthis socket, this Specification of Letters Patent.

Patented Oct. 28, 1919.

1916. Serial no. 82338.

- plug being more clearly shown in Figs. 2, 3

and 4. This plug consists of two separable body members 5 and 6. The member 5 is made of insulating material and does not carry the customary screw shell on its periphery, but has its insulating body portion formed with a screw threaded periphery as clearly apparent from the figures. This body member has a central contact element 7' which, when this body member is in position, cooperates with the central contact element 2 of the socket. The contact member 7 is extended upwardly as shown at 8 and may terminate in a spring contact finger 9, which spring contact member projects into the open space 10 that is formed within this body member 5.' The said body member 5 also has a further open a groove, at which point a portion of the periphery, as shown more clearly in Figs. 2 and 3, is cut away. This groove extends as a slot 11 preferably where it passes through the portion 12 which is supposed to be grasped by the fingers when inserting this body member 5 into the socket if it should be desired to insert this body member independently of the body member 6. The cooperating body member 6 has a spring contact finger 13 which is fixedly secured to said body member and which is adapted to project lnto the open space 10 and form electrical'contact with the spring contact finger 9 when these two cooperating members are in their unseparatcd condition as shown in Fig. 1. This body member 6 further has a second spring contact finger 14. The contact fingers 13 and 14 are then adapted respectively to be electrically connected with the entering cord members 15 and 16. The spring finger 14 is adapted to enter through the slot'11 and then projects into the open space 10 where, by reasonof its spring action, if the plug is not in the socket this spring finger 14 normally p'rojects outwardly beyond the periphery slightly of said body member 5. Thus it will be seen that this spring contact finger 14' itself normally engages the inner screw threaded contact?) of the socket when the plug is in position as shown in Fig. 1.

Now assume that it is desired to disconnect the circuit, then thebody member 6 (Fig. 1) is pulledto the right, whereupon the spring finger 14 is pulled'away from its association with the contact 3 and the spring finger 13 is also drawn away from engagement with the spring linger 9. ihus the body member 5 has provision for containing.

only one side of the circuit, the other side of the circuit being accommodated for and its continuity provided for solely by the means associated with the body member 6.

It will be seen that the two elements of the pin are normally yieldingly locked toget or as they should be, the particular means herein shown to serve this purpose being the ofi'set portions of the springfin gersl) and 13, as shown for instance at 17.

for the conductiiw portion of but one side of the circuit. Taegreat simplicity of thus constructing a plug will be readily apparent as it is seen that the plug comprises very few parts and yet serves the purposes normally served by separable attachment plugs.

Referring more particularly to Figs. 7 and 9, I show a modified form of plug having a central contact 22 and an outer screw threaded contact 23 which extends only along a portion of the periphery of this plug, as shown more clearly in Fig. 9. This provides a cheap plug construction in that the central contact 22 andthe-screw threaded portion 23 can both be provided with (3X- tending spring contact fingers 24 and 2:3 to which the spring fingers 26 and 27 oi the separable portion 28 of the plug find rea 'y attachment.

I Fig. 5 I show an improved style of soctet construction in which the socket 18 has the customary central contact 19 and the customary screw threaded contact portion 20. The sockchlti, is designed for instance for wall purposes. in sockets of this nature the plug is frequently removed, thus leaving the inner portion of the socket 0X- poscd and it very frequently happens that children insert their fingers into the socket and thus receive. a shock by touching both thetcrminals l!) and 20. My improved socket I tU'OHlS l'llN difficulty by providing a conducting finger 29 insulatingly mounted in the socket. Finger 2S) shields the central contact 19. Thus if the finger is inserted into the socket no shock would be obtained as tho linger 29 normally does not engage the contact 19. The danger of shock is thus entirely avoided, but it will of course be readily apparent that when a plug is inserted and screwed into the socket, that lhc spring finger 29 is then bent to engage. the center contact 19 and thus establish continuity of the circuit. When the plug is withdrawn, however, the spring finger 29 again assumes the position shown in Fig. 5 and safeguards against shockr l rom what has thus been described it is thought the nature of my invention will be clear to those skilled in the art. Having however thus described specific means for carrying out my invention, What I claim as 'new and desire to secure by Letters Patdescribed comprising two separable body InOllllJQlS, one of said body nibinbers havingmeans adapted to hold it in a socket having a screw threaded contact terminal, said other body member having two contact terminals," the outer one of which is adapted to directly engage the screw threaded contact terminal of said socket, and means for yieldingly locking said body members togather, said first aforesaid body member having a conducting portion adapted to enthe other terminal of said socket, and separable conducting means provided on said body members adapted for electrical association with said last aforesaid c0nducting portion. p

3. A connecting device of the character described comprising two separable body members, one of said body members having means adaptechto hold it in a socket having a screw threaded contact terminal, said other body member having two contact terminals", the outer one of which is adapted to directly engage the screw threaded contact terminal of said socket, and means for yivldingly locking said body members togcthcr, said first aforesaid body member having a conducting portion adapted to engage the other terminal of said socket, and separable conducting moans provided on said body members adapted for electrical association with said last aforesaid conducting, portion, said first aforesaid body member having a cut away portion to accommodate the contact terminal ol said second body member which is adapted directly to engage a socket terminal.

4. A connectingdevice of the character described comprising two scparablcbody members, (mo of said body members having means adapted to hold it 'n a socket having a screw threai'lcd contact terminal, said other body member having two spring con members together.

tact terminais, the outer one of "Wnich is adapted to directiy engage the fem-aw thromn-d contact tenninai of said socket, am] 1110:1115 for yielding lvjuicing sai'ii body A mnnectins deYii-e M L dQSCYibQi cmnpr mg W0 sepzu'a members" one of said body inmnbera imvi'zig means; adapted to noid "it in a mvkvt having a SCl'CW threaded Contact "mi, said. other body member 12: vying described, cmnpirfiing two sepai'nbl I bmiy menmei's, one of said back; memb v in Ring means adapted to hold it in sm'ker having a screw threaded contzut tennimi, said other body member having two spring connmmhu' for a'm'civing H10 terminals of a con- T. f-i column-ting device 0% the vhmm'ta? (EL-scribed ('()I11] )'i'ifiil1l" two scpuirnbic body members, mm of said body members having means adapted whom it in :1 gun-hot having a SCL'HW, threaded commit i'uz'minzil, said other body munflm' mvin z two mntzugt iii;- minzlirs, one of \Vhii'i. is adapted in (firm-Hy engzzg; the sm'cw Hn'vudml ('fmi'zut fvz'minai (if said Qcket.

.UAVID D. GORDOH. 

